The Neuropsychology Core (NC) will provide standardized neuropsychological (NP) evaluations of patients and normal controls. the core will characterize, across clinical projects, the level and shape of NP profiles of patients with schizophrenia, temporal lobe epilepsy, Parkinson's Disease and probably dementia of the Alzheimer's Type, and help establish the relationship between behavioral dimensions and the anatomic and physiologic data. Examples of cross-project hypotheses are predicted relationships between organization or "executive" functions and anterior brain regions, informational processes and posterior regions, and memory functions with the temporal-hippocampal system. The main methodological thrust is the combined use of clinically established NP tests and novel experimental neurocognitive techniques. Thus, a major role for this core is the development and validation of cognitive activation procedures for use in the PET studies. It will also perform standardized screening and evaluation of medical, neurologic, and psychiatric function of the control group. Demographically stratified normative data is necessary for testing the proposed hypotheses, and this will also be a valuable contribution to NP assessment. The core will provide topographic display and analyses of the NP data. The resulting regional or "lobar" values will be systematically related to anatomic and metabolic data across populations. In addition to supporting the clinical projects, it is anticipated that this core will generate improvements in methodology and new information on the regional brain systems underlying neurocognitive functions.